Imaging
Figure 1: GE Healthcare Vscan Pocket-size Echocardiography
AB data.3–8
Their results cannot be extrapolated to a clinical scenario in which a PSE device would be used by a trainee. Even with high-end digital echocardiographic machines, the accuracy of echocardiographic data is operator-dependent, and this will only be amplified with PSE.4,8
With PSE, the adequate storage of ultrasound
Figure 2: Insufficent Endocardial Border Delineation with Pocket-size Echocardiography Improved After the Injection of Sonovue
AB C
pictures and loops is crucial, especially if the focus of the use of the PSE device is the evaluation of left-ventricular function and cavity size. Cardiac ultrasound specialists will unanimously confirm that the adequate interpretation of regional wall motion abnormalities, integrating wall motion and thickening, is one of the most difficult tasks in cardiac ultrasound, requiring the highest expertise and perfect endocardial border determination (see Figure 2).
If PSE is to be introduced for point-of-care cardiac ultrasound in the A&E department, education and training will be of the utmost importance, since it will be less experienced physicians who will perform the examination and interpret the findings. Introducing a PSE device in the A&E department in the hands of non-experts could also raise medico-legal issues. The A&E department is a stressful environment, with critically ill patients, time constraints, technical acquisition problems and limited time for consulting with other staff members. Critical decisions have to be made and medical errors are likely to occur.9
Any change in strategy that may potentially increase the DE F
risk of errors must therefore be avoided. Technical Shortcomings
Enhancement of endocardial border during Vscan imaging with contrast. End-diastolic views with and without contrast in apical 4 chamber view (A–B), apical 2 chamber view (C–D) and apical 3 chamber view (E–F).
The same authors found that the increase in the duration of the consultation using PSE on top of the stethoscope was only 180±86 seconds (range 45–420 seconds).6
routine examinations and, to a lesser extent, in more appropriate referrals. Cardim et al. showed that physical examination only and physical examination plus PSE both came to the same conclusion regarding referral to the echocardiography laboratory in 19.6 % of patients; however, physical examination plus PSE resulted in the additional referral of another 14.3 % of patients, and found that a further 30.7 % of patients had been inadequately referred by physical examination only.6
PSE is an amazing piece of technology, but it still has shortcomings. The resolution of the images is pretty good, but the screen of course is small, making the detection of small abnormalities difficult. The accurate detection of small abnormalities, such as vegetations in endocarditis, is crucial in clinical diagnosis, especially in the emergency setting. The examination performed with a PSE device is not a complete echocardiographic examination. Major tools such as pulsed wave (PW) Doppler, continuous wave (CW) Doppler and tissue Doppler imaging are still lacking. Considering its shortcomings, PSE can only provide semi-quantitative information of the anatomy and haemodynamics of the heart. One can visualise aortic valve sclerosis, but cannot diagnose severe aortic valve stenosis with absolute certainty. One can use colour Doppler regurgitant flow jets to estimate valvular regurgitations, but cannot accurately quantify clinically important regurgitations, since no quantitative Doppler tools are available. Echocardiography laptops can be integrated in the hospital’s electronical system, and examinations performed in the A&E department can therefore be followed and supervised by an expert at the central echocardiography laboratory. This not yet possible with a PSE device.
Galderisi et al. and Liebo et al. clearly demonstrated that the results obtained with PSE were significantly better when it was used by experienced practitioners compared with trainees.4,8
Galderisi et al.
found a sensitivity and specificity of the PSE device, compared to the highendechocardiographic machine as the reference technique are 97 % and 84 % for experts and 87 % and 72 % for trainees.4
Important Issues to Resolve in the Setting of the Accident and Emergency Department Education and Training
Most of the studies showing the excellent accuracy of PSE, compared with the reference high-end digital ultrasound systems, used trained ultrasonographers or cardiologists to analyse and store the image
106
Strategic Distribution of Cardiac Ultrasound Examinations in Emergency Settings
The same discussion about the risks and benefits of introducing a new imaging device in cardiac ultrasound practice took place when the echocardiography portable computer (echo-PC) was introduced. Mobile portable computer ultrasound systems are now widely used in A&E departments. The broader question is: does everybody need an ultrasound stethoscope in their pocket, in A&E departments where ultrasound systems with better spatial resolution and better digital storage and transmission capacities, as well as fully equipped platforms with all Doppler modalities included, are already available? Of course, an exception to this is the ambulance, where introducing PSE would provide a new and unique cardiac imaging modality.
EUROPEAN CARDIOLOGY
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